#include <string>  
using namespace std;


class SalesItem {  
	private:  
	string _bookNo;  
	int _unitsSold;  
	double _sellingPrice;  
	double _salePrice;  
	int _discount; 
	
	public:  
	SalesItem();  
	SalesItem(const string& bookNo, int unitsSold, double sellingPrice, double salePrice, int discount);  
	
	 
	string isbn() const;  
	
	  
	void input();  
	
	  
	void output() const;  
	
	 
	SalesItem& operator=(const SalesItem& other);  
	
	
	void combine(const SalesItem& other);  
};  


